1. Field of the Invention
The present invention relates to a method, system, and program for managing storage units in storage pools.
2. Description of the Related Art
In a tape library system, a tape controller will perform a reclamation process to improve the utilization of the tape storage units. The reclamation process involves copying active data from one or more tapes having both inactive and active data to fewer tapes that only have active data. The tapes from which the data is copied are then added to a scratch pool of available tapes from which they may be selected and used to store future data. Empty tapes may be returned to a scratch pool or retained for exclusive use of the current pool. This process improves storage capacity utilization by aggregating active data from multiple tapes to a single tape that stores a greater percentage of active data. Reclamation is necessary because as data is modified, older versions of the data on various tapes becomes outdated or inactive. Tapes that have both inactive and active data are not fully utilized because data is written sequentially and inactive data cannot simply be replaced with active data.
Notwithstanding the prior art techniques for managing data across multiple tapes, there is a need for improved techniques for managing data stored in multiple tape cartridges.